In a wire harness used for automobiles and the like, a plurality of electric wires, which are formed of insulated electric wire conductors, are bound to each other, connecting terminals are arranged on electric wire ends, and further, the connecting terminals are accommodated in a connector housing to form a connector.
Conventionally, a wire harness is manufactured by being subjected to processes of electric wire cutting, removing coating of ends, connecting terminals (crimping or pressure welding), and inserting connectors, in this order.
Among the above-mentioned processes, a cutting process for an electric wire is a process to cut an electric wire one by one to have a predetermined length. The coating removing process for an end is a process to expose an electric wire conductor by removing a part of an insulating coating. Further, the terminal connecting process is a process of crimping or pressure welding terminals to an exposed electric wire conductor. In a case of pressure welding, sometimes, a terminal can be connected to an electric wire conductor even an insulating coating remains thereon.
The connector inserting process is the process of repeating collecting predetermined electric wires with terminals for each wire harness and inserting the terminals into a predetermined position in the connector housing. After the connector inserting process, the bound electric wires are finally secured with a tape or the like to form a set of wire harness. The processes are performed manually or with automated machines. Patent Document 1 as mentioned below discloses an example of manufacturing a wire harness.
Among the processes as described above, in the electric wire end treatment process from the electric wire cutting process to the terminal connecting process, changeover of a supply portion for electric wires and/or a supply portion for components to be assembled such as terminals and the like, and a connecting portion (crimping portion) for connecting (crimping) components to be assembled such as terminals to the ends is performed so as to handle manufacturing multiple types of electric wires which are treated at ends.
Conventionally, in order to mitigate temporal load and/or operational load required for the changeover as mentioned above, in general, so-called a lot production method is employed. In this method, multiple wires are collectively subjected to end treatment for every type of electric wires which will be required, and electric wires subjected to the end treatment are temporarily stored as a middle stock.
In the lot production method, for example, as in a manufacturing process for wire harnesses shown in FIG. 19, multiple types (two types in the figure) of electric wires are respectively manufactured by the changeover using multiple (three in the figure) electric wire end treatment devices. In FIG. 19, the electric wire end treatment devices manufacture electric wires W1, W3, and W5, which have different lengths, different types of terminals connected thereto, and the like. Then, after the changeover, they further manufacture electric wires W2, W4, and W6 of different types.
Next, when the end treatment process in the electric wire end treatment device is finished, the electric wires W1 through W6 are sorted and temporarily stored in predetermined storage spaces provided in a factory for each of the type. The temporarily stored electric wires W1 through W6 are moved to a subsequent process by a worker who manually retrieves a necessary one from the stored multiple types of electric wires.
A process subsequent to the electric wire end treatment process may be, for example, a twisting process for twisting a multiple electric wires to entangle, a jointing process for connecting ends of multiple wire harnesses, a sub-assy process for previously integrating a part which form wire harnesses used one vehicle, and the like.
Actually, the above-mentioned electric wires W1 through W6 are moved to the sub-assy process after the twisting process, jointing process or the like, or directly to the sub-assy process, depending upon the types of the vehicles to which the wire harnesses are assembled and the like. A group of electric wires assembled in the sub-assy process are transferred on an assemble conveyer, subjected to processes such as connector inserting and the like, and then moved to a final assembling process for forming wire harnesses for one vehicle.
In the lot production method as described above, if a large number of types of the electric wires are stored the storing spaces, the operation to manually retrieve the electric wires W1 through W6 which will be required in the subsequent process of the electric wire end treatment process becomes complicated, and there is a risk that a worker erroneously retrieves different types of electric wires. For such a reason, manufacturing defects such as erroneous integration tend to occur.
Further, if the electric wires subjected to the end treatment are mounted without being organized based on their types, it takes time to find out a target electric wire for the subsequent process, or the electric wires tangle to each other, thereby making them difficult to be retrieved. Accordingly, the productivity has been low.
Patent Document 2 mentioned below discloses providing an electric wire supply shelf for sorting the electric wires subjected to the end treatment into different types and storing them in a storage space provided adjacent to the electric wire end treatment device. In the Patent Document 2 mentioned below, a plurality of holders for accommodating sorted electric wires for different types are set to the electric wire supply shelf. A lid is provided for each holder, and only a lid corresponding to an electric wire which will be required at the subsequent process is automatically opened in order to suppress erroneous assembly.